The semiconductor integrated circuit (IC) industry has experienced rapid growth. Continuing advances in semiconductor manufacturing processes have resulted in semiconductor device structures with finer features and/or higher degrees of integration. Functional density (i.e., the number of interconnected devices per chip area) has generally increased while feature size (i.e., the smallest component that can be created using a fabrication process) has decreased. The scaling-down process generally provides benefits by increasing production efficiency and lowering associated costs.
The recent trend in miniaturizing IC has resulted in smaller devices which consume less power yet provide more functionality at higher speeds. However, the miniaturization process has also resulted in stricter design and manufacturing specifications as well as reliability challenges. For one or more of these advantages to be realized, various developments in IC design and/or manufacture are considered. Stress Migration (SM) is a failure mechanism that occurs in integrated circuit metallization from the formation of voids between grain boundaries. As IC's are further reduced in size, new SM failure modes in interconnect structures are discovered affecting IC performance and/or reliability.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale.